Method and machine for forming plastic spirals



Nov. 28, 1944. M. YELLIN 2,353,826

\ N METHOD AND MACHINE FOR FORMING PLASTIC SPIRALS Filed March 19, 1942 '5 Sheets-Sheet 1.

Nov. 28, 1944. M, YELLIN METHOD AND MACHINE FOR FORMING PLASTIC SPIRALS 5 Sheets-Sheet 2 Filed March 19, 1942 3% w MW QM www l Nov. 28; 1944. M. YELLIN 2,353,826

METHOD AND MACHINE FOR FORMING PLASTIC SPIRALS Filed March 19, 1942 3 Sheets-Sh eet 3 Patented Nov. 28, 1944 PATENT OFFICE zgssaszs METHOD AND MACHINE FOR FORMING PLASTIC SPIRALS -Morrls Yellin, Chicago, Application March 19, 1942, Serial No. 435,425

4 Claims.

1 ed plastic material from its holder, heat it to proper temperature as it is advancing then wind it to form a continuous spiral.

Another object is to provide a machine which can be readily changed to form plastic spirals of any desired pitch or circumference as well as spirals from extruded plastic materials which in transverse cross section are either round, fiat or other desired shape.

In the drawings:

Fig.1 is a perspective view of the machine I forming this invention and showing the heating compartment moved away from the plate member.

showing the spiral forming apparatus.

Fig. 3 is a view taken on line 3-3 of Fig. 2. Fig. 4 is a cross sectional view taken on line ll-l of 2.

Fig. 5 is an elevational view taken 5-5 of Fig. 2. v

Fig. 6 is a perspective view of the guide finger. Fig. 7 is a side elevational view of the spiral 011 line 2 formed with this machine. and.

Fig. 8 is a side elevational view of a fiat type of spiral that can he formed with the machine. The machine has a case 10 with an upright metal plate or block H secured to said base as at 12. Hingedly secured to the plate as at I3 is a housing generally indicated at H within which is supported the electrical heating elements generally indicated at 15, mounted on insulating members [5a.

Supported on suitable shafts IS on the plate H in staggered relation are grooved guide wheels I! which are freely rotatable about their slmits. The wheels are positioned adiacent the opposite ends of the plate to provide the maximum travel distance for the extruded strand of plastic ma-- terial through the heated area to be described. Anarm ltissecuredtotheplate ll andthis arm supports a U shaped member I! which re- Fig. 2 is a plan view partially in cross section ceives and supports material 2].

Positioned forwardly of the plate I I and secured to the base 10 is a block 22 which is verti- 5 cally channelled as at 23. Supported within the channel 23 is an end bearing 24' which is secured to the block 22-by a threaded bolt 25.

The bearing 24 supports one end of the shaft 26.

The opposite end of the shaft is supported in a bearing block 21 which in turnjs secured to the base It! by a threaded bolt 28'. Fixedly mounted on the shaft 26 is a roller 25 which has an annular groove 30. One endof the roller is provided with gear teeth 35. Fixedly mounted on the shaft 26 as by a set screw 32 is a gear 33. Slidably mounted in the block 22 is a block 3: 1 which through a shaft 35 rotatably supports a roller 36. This roller has an annular groove 3! which is in alignment with the groove 3!! and has teeth 38 which are in engagement with the teeth iii. A right angled bar 39 is secured to the block 22 by bolts #0 and the horizontal arm 3%. of same supports a threaded bolt t! which retains a dished washer d2- interposed between the top of the block and the washer 42 is a coiled spring 43 which maintains the block under constant pressure to maintain the rollers 2t and 35 under pressure.

Suitably secured to the base it is a U shaped 9 member A l. The-arms a and Nb of same are each provided with an opening which receive roller bearings 35. Rotatahly mounted to rotate within said hearings is a sleeve 4?. Secured to said sleeve by a set screw 48 is a combined 35 puller l9 and gear 59. Rotataoly supported on it a shaft 59 which is secured to the arm 44!: is an intermediate gear 52 which engages the gears 33 and 50. The pufiey I9 is connected by a belt 53 to a motor or other suitable source of driving power that shown) and is driven thereby.

Supported on the base is a post 51 to which is secured an arbor or mandrel generally indicated at 55. The mandrel is secured to the post by means of its threaded end portion 55a which is engaged by a nut 55. The mandrel has a helicfi or spiral moove 51 substantially throughout its length and said mandrel passes into the sleeve 12' and hassle extension 58 extending beyond the edge of the sleeve.

Positioned between the rollers 2545 and the mandrel 55 is a guide finger generally indicated at fill, which has one of its ends provided with tapering portions SI and 82 so that same can iii:v adjacent the two rollers 29 and 38. The op- 55 posite end of the guide finger has a hook 63 a spool 20 of extruded plastic which hooks over the mandrel 55 adjacent the entrance to the sleeve 41. The member has a bore 64 and the opening of same at one end is adjacent the grooves 31 and 30 of the rollers, while at the other end it is adjacent the mandrel at the entrance of the sleeve.

A member is fixedly mounted on the mandrel 55 and supports a set screw H which engages the hooked end 63 and serves to retain the guide finger 60 in a proper operating posi- .covering 66 is positioned in the compartment to the front of the heating elements. The side and bottom of the housing are provided with suitable cutout portions to permit the housing to be moved adjacent the plate ii and locked thereto by'the locking means 31 without interferingwith the travel of the extruded plastic.

The operation of the machine will now bedescribed.

The extruded strip or strand of plastic 2| which is on the spool is initially threaded through an eyelet T2 andpassed around the grooves of the guide wheels I! in the order shown in Fig. 1, so that the plastic strand will travel back and forth several times across the heated area, then between the grooves 30 and 3'l-of the rollers 36 and 29, through the bore 64 in the guide finger 60 and the end of said strand is placed in the groove 51 of the mandrel 55 adjacent the entrance to the sleeve 47. The heating compartment I4 is moved to closed position with the heatascasac the plastic strand passes back and forth through a sufficiently large heated area so that the plastic strand becomes sufficiently soft and pliable when it is fed into the sleeve. As it passes along the mandrel and sleeve, it sets and forms the spiral. It can be then cut in any desired lengths.

While I .have shown only one type of spiral coil produced in the machine, this is only for the purpose of illustration, it being understood that spirals of any desired pitch or circumference can be produced merely by removing the mandrel 55 and substituting in lieu thereof a mandrel having grooves of a diiferent pitch. If a larger circumference is desired a larger sleeve and a coring elements proximate to the reversed strand I carried on the rollers. The electrical current is turned on for imparting heat to the heating elements l5. The motor or source of power (not shown) is turned on and through the belt 53 will drive the pulley 49 which is fixed to the sleeve 41 to rotate the sleeve about the mandrel 55. Simultaneously therewith the gear 50 will be rotating which will drive the intermediate gear 52 to rotate the gear 33 in the same direction as gear 50. Rotation of the gear 33 will rotate the shaft 26 on which is secured the roller 29 which rotates therewith. Rotation of the roller 29 will through the teeth 3| and 38 rotate the roller 35. The rotation of the rollers 29 and 36 will pull the plastic strand forwardly unwinding. same from itsspool 23 and around the guide wheels I! and through the grooves of the rollers 29 and '36 to feed it to the mandrel around the grooves thereof and through the sleeve to form a continuous spiral.

The rollers 29 and 36 in the first instance serve to pull the strand to the rollers and when it passes the rollers they serve to push the strand throughrespondingly larger mandrel can be substituted for that shown.

Other types of spiral plastic coils, such as fiat strips shown in Fig. 8 can'likewise be produced. If such type of spiral is desired, a fiat strip of extruded material is used and a mandrel formed with grooves having a rectangjlar cross section is substituted for the 'mandr 1 shown in the drawings.

Various changes may be made without departing from the invention, and hence I do not limit myself to the precise details set forth, but consider myself at liberty to make such changes and alterations as fairly fall within the spirit and scope of the appended claims.

I claim:

1. The method of forming a spiral from plastic strand material which comprises, continuously withdrawing a strand of plastic material from a source of supply, rendering the strand soft and pliable after being drawn from the supply, continuously pushing the softened strand between a stationary spirally grooved mandrel and an arcuate stationary guide to shape the strand into a coil about one end of the mandrel, and thereafter confining the coil shaped strand within the groove of the mandrel while continuously feeding the same therealong and expelling the formed spiral from the mandrel.

2. In a machine of the character described, a heating chamber, a spirally grooved fixed mandrel remote from the heating chamber, a sleeve rotatable about said mandrel, a stationary arcuate guide curved about one end of the mandrel and adjacent one end of the sleeve, said guide 'being constructed and arranged to cooperate with the mandrel to shape the strand into a coil, means disposed between the heating chamber and mandrel for drawing a strand of plastic material from a source of supply through the heating chamber and pushing same through the stationary curved guide, the inner surface of the sleeve being cylindrical throughout its length and engageable with the strand to feed it along the grooved mandrel.

3. In a machine of the character described having opposed strand feeding rollers, a fixed spirally grooved mandrel, and a'sleeve rotatable about the mandrel for feeding the strand through the groove thereof, a strand guiding finger disposed between the rollers and the mandrel, and said finger having a bore for passage of said strand and a hooked end forming an arcuate extension of one wall of the bore engageable over the mandrel adjacent onfe end of the sleeve.

4. The. structure according to claim 3 together with adjustable meansl engageable with said finger to hold said hooked end adjacent the entrance end of the sleeve.

MORRIS YELLIN. 

